');
foreach ($build_modes as $build_mode => $label) {
$display = isset($instance['display'][$build_mode]) ? $instance['display'][$build_mode] : $instance['display']['full'];
$form[$name][$build_mode]['label'] = array(
'#type' => 'select',
'#options' => $label_options,
'#default_value' => $display['label'],
);
$form[$name][$build_mode]['type'] = array(
'#type' => 'select',
'#options' => $formatter_options,
'#default_value' => $display['type'],
);
}
}
$form['submit'] = array('#type' => 'submit', '#value' => t('Save'));
return $form;
}
/**
* Theme preprocess function for field_ui-display-overview-form.tpl.php.
*/
function template_preprocess_field_ui_display_overview_form(&$vars) {
$form = &$vars['form'];
$contexts_selector = $form['#contexts'];
$vars['contexts'] = field_ui_build_modes_tabs(field_info_bundle_entity($form['#bundle']), $contexts_selector);
$order = _field_ui_overview_order($form, $form['#fields']);
if (empty($order)) {
$vars['rows'] = array();
$vars['submit'] = '';
return;
}
$rows = array();
foreach ($order as $key) {
$element = &$form[$key];
$row = new stdClass();
foreach (element_children($element) as $child) {
if (array_key_exists('label', $element[$child])) {
$row->{$child}->label = drupal_render($element[$child]['label']);
$row->{$child}->type = drupal_render($element[$child]['type']);
}
else {
$row->{$child} = drupal_render($element[$child]);
}
}
$row->label_class = 'label-field';
$rows[] = $row;
}
$vars['rows'] = $rows;
$vars['submit'] = drupal_render_children($form);
}
/**
* Submit handler for the display overview form.
*/
function field_ui_display_overview_form_submit($form, &$form_state) {
$form_values = $form_state['values'];
foreach ($form_values as $key => $values) {
if (in_array($key, $form['#fields'])) {
$instance = field_info_instance($key, $form['#bundle']);
foreach ($instance['display'] as $build_mode => $display) {
if (isset($values[$build_mode])) {
$instance['display'][$build_mode] = array_merge($instance['display'][$build_mode], $values[$build_mode]);
}
}
field_update_instance($instance);
}
}
drupal_set_message(t('Your settings have been saved.'));
}
/**
* Return an array of field_type options.
*/
function field_ui_field_type_options() {
$options = &drupal_static(__FUNCTION__);
if (!isset($options)) {
$options = array();
$field_types = field_info_field_types();
$field_type_options = array();
foreach ($field_types as $name => $field_type) {
// Skip field types which have no widget types.
if (field_ui_widget_type_options($name)) {
$options[$name] = $field_type['label'];
}
}
asort($options);
}
return $options;
}
/**
* Return an array of widget type options for a field type.
*
* If no field type is provided, returns a nested array of all widget types,
* keyed by field type human name.
*/
function field_ui_widget_type_options($field_type = NULL, $by_label = FALSE) {
$options = &drupal_static(__FUNCTION__);
if (!isset($options)) {
$options = array();
$field_types = field_info_field_types();
foreach (field_info_widget_types() as $name => $widget_type) {
foreach ($widget_type['field types'] as $widget_field_type) {
// Check that the field type exists.
if (isset($field_types[$widget_field_type])) {
$options[$widget_field_type][$name] = $widget_type['label'];
}
}
}
}
if (isset($field_type)) {
return !empty($options[$field_type]) ? $options[$field_type] : array();
}
if ($by_label) {
$field_types = field_info_field_types();
$options_by_label = array();
foreach ($options as $field_type => $widgets) {
$options_by_label[$field_types[$field_type]['label']] = $widgets;
}
return $options_by_label;
}
return $options;
}
/**
* Return an array of formatter options for a field type.
*
* If no field type is provided, returns a nested array of all formatters, keyed
* by field type.
*/
function field_ui_formatter_options($field_type = NULL) {
$options = &drupal_static(__FUNCTION__);
if (!isset($options)) {
$field_types = field_info_field_types();
$options = array();
foreach (field_info_formatter_types() as $name => $formatter) {
foreach ($formatter['field types'] as $formatter_field_type) {
// Check that the field type exists.
if (isset($field_types[$formatter_field_type])) {
$options[$formatter_field_type][$name] = $formatter['label'];
}
}
}
}
if ($field_type) {
return !empty($options[$field_type]) ? $options[$field_type] : array();
}
return $options;
}
/**
* Return an array of existing field to be added to a bundle.
*/
function field_ui_existing_field_options($bundle) {
$options = array();
$field_types = field_info_field_types();
foreach (field_info_instances() as $bundle_name => $instances) {
// No need to look in the current bundle.
if ($bundle_name != $bundle) {
foreach ($instances as $instance) {
$field = field_info_field($instance['field_name']);
// Don't show locked fields or fields already in the current bundle.
if (empty($field['locked']) && !field_info_instance($field['field_name'], $bundle)) {
$text = t('@type: @field (@label)', array(
'@type' => $field_types[$field['type']]['label'],
'@label' => t($instance['label']), '@field' => $instance['field_name'],
));
$options[$instance['field_name']] = (drupal_strlen($text) > 80 ? truncate_utf8($text, 77) . '...' : $text);
}
}
}
}
// Sort the list by field name.
asort($options);
return $options;
}
/**
* Menu callback; presents the field settings edit page.
*/
function field_ui_field_settings_form($form, &$form_state, $obj_type, $bundle, $instance) {
$bundle = field_extract_bundle($obj_type, $bundle);
$field = field_info_field($instance['field_name']);
// When a field is first created, we have to get data from the db.
if (!isset($instance['label'])) {
$instance = field_read_instance($field['field_name'], $bundle);
$field = field_read_field($field['field_name']);
}
$field_type = field_info_field_types($field['type']);
$info_function = $field['module'] . '_field_info';
$info = $info_function();
$description = '' . $info[$field['type']]['label'] . ': ';
$description .= $info[$field['type']]['description'] . '
';
$form['#prefix'] = '' . $description . '
';
$description = '' . t('These settings apply to the %field field everywhere it is used. These settings impact the way that data is stored in the database and cannot be changed once data has been created.', array('%field' => $instance['label'])) . '
';
// Create a form structure for the field values.
$form['field'] = array(
'#type' => 'fieldset',
'#title' => t('%field field settings', array('%field' => $instance['label'])),
'#description' => $description,
'#tree' => TRUE,
);
// See if data already exists for this field.
// If so, prevent changes to the field settings.
$has_data = field_attach_field_has_data($field);
if ($has_data) {
$form['field']['#description'] = '' . t('There is data for this field in the database. The field settings can no longer be changed.' . '
') . $form['field']['#description'];
}
// Build the non-configurable field values.
$form['field']['field_name'] = array('#type' => 'value', '#value' => $field['field_name']);
$form['field']['type'] = array('#type' => 'value', '#value' => $field['type']);
$form['field']['module'] = array('#type' => 'value', '#value' => $field['module']);
$form['field']['active'] = array('#type' => 'value', '#value' => $field['active']);
// Set translatability.
$form['field']['translatable'] = array(
'#type' => 'radios',
'#title' => t('Multilingual settings'),
'#options' => array(TRUE => t('Translatable field'), FALSE => t('Language neutral field')),
'#default_value' => $field['translatable'],
'#description' => t("Translatable fields can have a different value for each available language. An example of a translatable field is an article's body. Language neutral fields will retain the same value across all translations. An example of a language neutral field is a user profile's first name."),
);
// Add settings provided by the field module. The field module is
// responsible for not returning settings that cannot be changed if
// the field already has data.
$form['field']['settings'] = array();
$additions = module_invoke($field_type['module'], 'field_settings_form', $field, $instance, $has_data);
if (is_array($additions)) {
$form['field']['settings'] = $additions;
}
if (empty($form['field']['settings'])) {
$form['field']['settings'] = array(
'#markup' => t('%field has no field settings.', array('%field' => $instance['label'])),
);
}
$form['#bundle'] = $bundle;
$form['submit'] = array('#type' => 'submit', '#value' => t('Save field settings'));
return $form;
}
/**
* Save a field's settings after editing.
*/
function field_ui_field_settings_form_submit($form, &$form_state) {
$form_values = $form_state['values'];
$field_values = $form_values['field'];
// Merge incoming form values into the existing field.
$field = field_info_field($field_values['field_name']);
$bundle = $form['#bundle'];
$instance = field_info_instance($field['field_name'], $bundle);
// Update the field.
$field = array_merge($field, $field_values);
try {
field_update_field($field);
drupal_set_message(t('Updated field %label field settings.', array('%label' => $instance['label'])));
$form_state['redirect'] = field_ui_next_destination($bundle);
}
catch (FieldException $e) {
drupal_set_message(t('Attempt to update field %label failed: %message.', array('%label' => $instance['label'], '%message' => $e->getMessage())), 'error');
// TODO: Where do we go from here?
$form_state['redirect'] = field_ui_next_destination($bundle);
}
}
/**
* Menu callback; select a widget for the field.
*/
function field_ui_widget_type_form($form, &$form_state, $obj_type, $bundle, $instance) {
$bundle = field_extract_bundle($obj_type, $bundle);
$field = field_read_field($instance['field_name']);
$field_type = field_info_field_types($field['type']);
$widget_type = field_info_widget_types($instance['widget']['type']);
$bundles = field_info_bundles();
$bundle_label = $bundles[$bundle]['label'];
$form['basic'] = array(
'#type' => 'fieldset',
'#title' => t('Change widget'),
);
$form['basic']['widget_type'] = array(
'#type' => 'select',
'#title' => t('Widget type'),
'#required' => TRUE,
'#options' => field_ui_widget_type_options($field['type']),
'#default_value' => $instance['widget']['type'],
'#description' => t('The type of form element you would like to present to the user when creating this field in the %type type.', array('%type' => $bundle_label)),
);
$form['#instance'] = $instance;
$form['submit'] = array('#type' => 'submit', '#value' => t('Continue'));
$form['#validate'] = array();
$form['#submit'] = array('field_ui_widget_type_form_submit');
return $form;
}
/**
* Submit the change in widget type.
*/
function field_ui_widget_type_form_submit($form, &$form_state) {
$form_values = $form_state['values'];
$instance = $form['#instance'];
$bundle = $instance['bundle'];
// Set the right module information.
$widget_type = field_info_widget_types($form_values['widget_type']);
$widget_module = $widget_type['module'];
$instance['widget']['type'] = $form_values['widget_type'];
$instance['widget']['module'] = $widget_module;
try {
field_update_instance($instance);
drupal_set_message(t('Changed the widget for field %label.', array('%label' => $instance['label'])));
}
catch (FieldException $e) {
drupal_set_message(t('There was a problem changing the widget for field %label.', array('%label' => $instance['label'])));
}
$form_state['redirect'] = field_ui_next_destination($bundle);
}
/**
* Menu callback; present a form for removing a field from a content type.
*/
function field_ui_field_delete_form($form, &$form_state, $obj_type, $bundle, $instance) {
$bundle = field_extract_bundle($obj_type, $bundle);
$field = field_info_field($instance['field_name']);
$admin_path = _field_ui_bundle_admin_path($bundle);
$form['bundle'] = array('#type' => 'value', '#value' => $bundle);
$form['field_name'] = array('#type' => 'value', '#value' => $field['field_name']);
$output = confirm_form($form,
t('Are you sure you want to delete the field %field?', array('%field' => $instance['label'])),
$admin_path . '/fields',
t('If you have any content left in this field, it will be lost. This action cannot be undone.'),
t('Delete'), t('Cancel'),
'confirm'
);
if ($field['locked']) {
unset($output['actions']['submit']);
$output['description']['#markup'] = t('This field is locked and cannot be deleted.');
}
return $output;
}
/**
* Remove a field from a content type.
*/
function field_ui_field_delete_form_submit($form, &$form_state) {
$form_values = $form_state['values'];
$field = field_info_field($form_values['field_name']);
$instance = field_info_instance($form_values['field_name'], $form_values['bundle']);
$bundles = field_info_bundles();
$bundle = $form_values['bundle'];
$bundle_label = $bundles[$bundle]['label'];
if (!empty($bundle) && $field && !$field['locked'] && $form_values['confirm']) {
field_delete_instance($field['field_name'], $bundle);
// Delete the field if that was the last instance.
if (count($field['bundles'] == 1)) {
field_delete_field($field['field_name']);
}
drupal_set_message(t('The field %field has been deleted from the %type content type.', array('%field' => $instance['label'], '%type' => $bundle_label)));
}
else {
drupal_set_message(t('There was a problem removing the %field from the %type content type.', array('%field' => $instance['label'], '%type' => $bundle_label)));
}
$admin_path = _field_ui_bundle_admin_path($bundle);
$form_state['redirect'] = field_ui_get_destinations(array($admin_path . '/fields'));
}
/**
* Menu callback; presents the field instance edit page.
*/
function field_ui_field_edit_form($form, &$form_state, $obj_type, $bundle, $instance) {
$bundle = field_extract_bundle($obj_type, $bundle);
$field = field_info_field($instance['field_name']);
$form['#field'] = $field;
if (!empty($field['locked'])) {
$form['locked'] = array(
'#markup' => t('The field %field is locked and cannot be edited.', array('%field' => $instance['label'])),
);
return $form;
}
$field_type = field_info_field_types($field['type']);
$widget_type = field_info_widget_types($instance['widget']['type']);
$bundles = field_info_bundles();
$title = isset($instance['label']) ? $instance['label'] : $instance['field_name'];
drupal_set_title(check_plain($title));
// Create a form structure for the instance values.
$form['instance'] = array(
'#tree' => TRUE,
'#type' => 'fieldset',
'#title' => t('%type settings', array('%type' => $bundles[$bundle]['label'])),
'#description' => t('These settings apply only to the %field field when used in the %type type.', array('%field' => $instance['label'], '%type' => $bundles[$bundle]['label'])),
'#pre_render' => array('field_ui_field_edit_instance_pre_render'),
);
// Build the non-configurable instance values.
$form['instance']['field_name'] = array(
'#type' => 'value',
'#value' => $instance['field_name'],
);
$form['instance']['bundle'] = array(
'#type' => 'value',
'#value' => $bundle,
);
$form['instance']['widget']['weight'] = array(
'#type' => 'value',
'#value' => !empty($instance['widget']['weight']) ? $instance['widget']['weight'] : 0,
);
// Build the configurable instance values.
$form['instance']['label'] = array(
'#type' => 'textfield',
'#title' => t('Label'),
'#default_value' => !empty($instance['label']) ? $instance['label'] : $field['field_name'],
'#required' => TRUE,
'#description' => t('The human-readable label for this field.'),
'#weight' => -20,
);
$form['instance']['required'] = array(
'#type' => 'checkbox',
'#title' => t('Required'),
'#default_value' => !empty($instance['required']),
'#description' => t('Check if a value must be provided.'),
'#weight' => -10,
);
$form['instance']['description'] = array(
'#type' => 'textarea',
'#title' => t('Help text'),
'#default_value' => !empty($instance['description']) ? $instance['description'] : '',
'#rows' => 5,
'#description' => t('Instructions to present to the user below this field on the editing form.
Allowed HTML tags: @tags', array('@tags' => _field_filter_xss_display_allowed_tags())),
'#required' => FALSE,
'#weight' => 0,
);
// Build the widget component of the instance.
$form['instance']['widget']['type'] = array(
'#type' => 'value',
'#value' => $instance['widget']['type'],
);
$form['instance']['widget']['module'] = array(
'#type' => 'value',
'#value' => $widget_type['module'],
);
$form['instance']['widget']['active'] = array(
'#type' => 'value',
'#value' => !empty($field['instance']['widget']['active']) ? 1 : 0,
);
// Add additional field instance settings from the field module.
$additions = module_invoke($field['module'], 'field_instance_settings_form', $field, $instance);
if (is_array($additions)) {
$form['instance']['settings'] = $additions;
}
// Add additional widget settings from the widget module.
$additions = module_invoke($widget_type['module'], 'field_widget_settings_form', $field, $instance);
if (is_array($additions)) {
$form['instance']['widget']['settings'] = $additions;
$form['instance']['widget']['active']['#value'] = 1;
}
// Add handling for default value if not provided by any other module.
if (field_behaviors_widget('default value', $instance) == FIELD_BEHAVIOR_DEFAULT && empty($instance['default_value_function'])) {
// Store the original default value for use in programmed forms. The
// '#default_value' property is used instead of '#value' so programmed
// values can override whatever we set here.
$form['instance']['default_value'] = array(
'#type' => 'value',
'#default_value' => $instance['default_value'],
);
// We cannot tell at the time we build the form if this is a programmed form
// or not, so we always end up adding the default value widget even if we
// will not use it.
field_ui_default_value_widget($field, $instance, $form, $form_state);
}
$info = field_info_field_types($field['type']);
$description = '' . $info['label'] . ': ';
$description .= $info['description'] . '
';
$form['#prefix'] = '' . $description . '
';
$has_data = field_attach_field_has_data($field);
if ($has_data) {
$description = '' . t('These settings apply to the %field field everywhere it is used. Because the field already has data, some settings can no longer be changed.', array('%field' => $instance['label'])) . '
';
}
else {
$description = '' . t('These settings apply to the %field field everywhere it is used.', array('%field' => $instance['label'])) . '
';
}
// Create a form structure for the field values.
$form['field'] = array(
'#type' => 'fieldset',
'#title' => t('%field field settings', array('%field' => $instance['label'])),
'#description' => $description,
'#tree' => TRUE,
);
// Build the configurable field values.
$description = t('Maximum number of values users can enter for this field.');
if (field_behaviors_widget('multiple values', $instance) == FIELD_BEHAVIOR_DEFAULT) {
$description .= '
' . t("'Unlimited' will provide an 'Add more' button so the users can add as many values as they like.");
}
$form['field']['cardinality'] = array(
'#type' => 'select',
'#title' => t('Number of values'),
'#options' => array(FIELD_CARDINALITY_UNLIMITED => t('Unlimited')) + drupal_map_assoc(range(1, 10)),
'#default_value' => $field['cardinality'],
'#description' => $description,
);
// Add additional field settings from the field module. The field module is
// responsible for not returning settings that cannot be changed if
// the field already has data.
$additions = module_invoke($field['module'], 'field_settings_form', $field, $instance, $has_data);
if (is_array($additions)) {
$form['field']['settings'] = $additions;
}
$form['submit'] = array('#type' => 'submit', '#value' => t('Save settings'));
return $form;
}
/**
* Pre-render function for field instance settings.
*
* Combines the instance, widget, and other settings into a single fieldset so
* that elements within each group can be shown at different weights as if they
* all had the same parent.
*/
function field_ui_field_edit_instance_pre_render($element) {
// Merge the widget settings into the main form.
if (isset($element['widget']['settings'])) {
foreach (element_children($element['widget']['settings']) as $key) {
$element['widget_' . $key] = $element['widget']['settings'][$key];
}
unset($element['widget']['settings']);
}
// Merge the instance settings into the main form.
if (isset($element['settings'])) {
foreach (element_children($element['settings']) as $key) {
$element['instance_' . $key] = $element['settings'][$key];
}
unset($element['settings']);
}
return $element;
}
/**
* Build default value fieldset.
*/
function field_ui_default_value_widget($field, $instance, &$form, &$form_state) {
$form['instance']['default_value_widget'] = array(
'#type' => 'fieldset',
'#title' => t('Default value'),
'#collapsible' => FALSE,
'#tree' => TRUE,
'#description' => t('The default value for this field, used when creating new content.'),
);
// Make sure the default value is not a required field.
$instance['required'] = FALSE;
$instance['description'] = '';
$items = $instance['default_value'];
// Set up form info that the default value widget will need.
$form['#fields'] = array(
$field['field_name'] => array(
'field' => $field,
'instance' => $instance,
),
);
function_exists('field_default_form');
// @todo Allow multiple values (requires more work on 'add more' JS handler).
$widget_form = field_default_form(NULL, NULL, $field, $instance, FIELD_LANGUAGE_NONE, $items, $form, $form_state, 0);
$form['instance']['default_value_widget'] += $widget_form;
$form['#fields'][$field['field_name']]['form_path'] = array(
'instance',
'default_value_widget',
$field['field_name'],
);
}
/**
* Validate a field's settings.
*/
function field_ui_field_edit_form_validate($form, &$form_state) {
$form_values = $form_state['values'];
$instance = $form_values['instance'];
$field = field_info_field($instance['field_name']);
$field_type = field_info_field_types($field['type']);
$widget_type = field_info_widget_types($instance['widget']['type']);
// Do no validation here. Assume field and widget modules are handling their
// own validation of form settings.
// If field.module is handling the default value, validate the result using
// the field validation.
if (field_behaviors_widget('default value', $instance) == FIELD_BEHAVIOR_DEFAULT) {
// If this is a programmed form, get rid of the default value widget, we
// have the default values already.
if (!empty($form_state['programmed'])) {
form_set_value(array('#parents' => array('instance', 'widget', 'default_value_widget')), NULL, $form_state);
return;
}
if (!empty($form_values['instance']['widget']['default_value_widget'])) {
// Fields that handle their own multiple values may use an expected value
// as the top-level key, so just pop off the top element.
$key = array_shift(array_keys($form_values['instance']['widget']['default_value_widget']));
$default_value = $form_values['instance']['widget']['default_value_widget'][$key];
$is_code = FALSE;
form_set_value(array('#parents' => array('instance', 'widget', 'default_value')), $default_value, $form_state);
}
if (isset($default_value)) {
$node = array();
$node[$field['field_name']] = $default_value;
$field['required'] = FALSE;
$field_function = $field_type['module'] . '_field';
$errors_before = form_get_errors();
// Widget now does its own validation, should be no need to add anything
// for widget validation here.
if (function_exists($field_function)) {
$field_function('validate', $node, $field, $default_value, $form, NULL);
}
// The field validation routine won't set an error on the right field, so
// set it here.
$errors_after = form_get_errors();
if (count($errors_after) > count($errors_before)) {
form_set_error('default_value', t('The default value is invalid.'));
}
}
}
}
/**
* Save instance settings after editing.
*/
function field_ui_field_edit_form_submit($form, &$form_state) {
$form_values = $form_state['values'];
$field_values = $form_values['field'];
$instance_values = $form_values['instance'];
$field_name = $instance_values['field_name'];
// Update any field settings that have changed.
$field = field_info_field($instance_values['field_name']);
$field = array_merge($field, $field_values);
field_update_field($field);
// Move the default value from the sample widget to the default value field.
if (isset($instance_values['default_value_widget'])) {
$langcode = $form['instance']['default_value_widget'][$field_name]['#language'];
$instance_values['default_value'] = $instance_values['default_value_widget'][$field_name][$langcode];
unset($instance_values['default_value_widget']);
}
// Update the instance settings.
$instance = field_info_instance($instance_values['field_name'], $instance_values['bundle']);
$instance = array_merge($instance, $instance_values);
field_update_instance($instance);
drupal_set_message(t('Saved %label configuration.', array('%label' => $instance['label'])));
$form_state['redirect'] = field_ui_next_destination($instance['bundle']);
}
/**
* Helper functions to handle multipage redirects.
*/
function field_ui_get_destinations($destinations) {
$query = array();
$path = array_shift($destinations);
if ($destinations) {
$query['destinations'] = $destinations;
}
return array($path, $query);
}
/**
* Return the next redirect path in a multipage sequence.
*/
function field_ui_next_destination($bundle) {
$destinations = !empty($_REQUEST['destinations']) ? $_REQUEST['destinations'] : array();
if (!empty($destinations)) {
unset($_REQUEST['destinations']);
return field_ui_get_destinations($destinations);
}
$admin_path = _field_ui_bundle_admin_path($bundle);
return $admin_path . '/fields';
}
/**
* Helper function to order fields when theming overview forms.
*/
function _field_ui_overview_order(&$form, $field_rows) {
// Put weight and parenting values into a $dummy render structure and let
// drupal_render() figure out the corresponding row order.
$dummy = array();
// Field rows: account for weight.
foreach ($field_rows as $name) {
$dummy[$name] = array(
'#markup' => $name . ' ',
'#type' => 'markup',
'#weight' => $form[$name]['weight']['#value'],
);
}
return $dummy ? explode(' ', trim(drupal_render($dummy))) : array();
}
/**
* Helper form element validator: integer.
*/
function _element_validate_integer($element, &$form_state) {
$value = $element['#value'];
if ($value !== '' && (!is_numeric($value) || intval($value) != $value)) {
form_error($element, t('%name must be an integer.', array('%name' => $element['#title'])));
}
}
/**
* Helper form element validator: integer > 0.
*/
function _element_validate_integer_positive($element, &$form_state) {
$value = $element['#value'];
if ($value !== '' && (!is_numeric($value) || intval($value) != $value || $value <= 0)) {
form_error($element, t('%name must be a positive integer.', array('%name' => $element['#title'])));
}
}
/**
* Helper form element validator: number.
*/
function _element_validate_number($element, &$form_state) {
$value = $element['#value'];
if ($value != '' && !is_numeric($value)) {
form_error($element, t('%name must be a number.', array('%name' => $element['#title'])));
}
}